Abstract: A displacement measurement device for a sensing device. The sensing device includes a first displacement sensor. The displacement measurement device includes: a drive signal generating circuit configured to output a drive signal to the first displacement sensor; a first signal processing circuit configured to receive a signal from the first displacement sensor and output a first ADSO signal; and a computing device including a first timer. The first timer is configured to receive a CLK512 signal and the first ADSO signal, and time or count according to the CLK512 signal and the first ADSO signal; and the CLK512 signal is a square wave signal related to a period and phase of the drive signal.

Abstract: Systems, methods, and devices improve the sensitivity of capacitive sensors. Devices may include an attenuator configured to receive an input from at least one sense electrode of a capacitive sensing device. The attenuator may be included in a sensing channel of a capacitive sensor. Devices may further include a signal generator coupled to an input of the attenuator. The signal generator may include one or more processors configured to generate a sinusoidal signal based, at least in part, on one or more noise characteristics of a scan sequence associated with one or more transmit electrodes of the capacitive sensing device, and provide the sinusoidal signal to the input of the attenuator.

Abstract: Systems and methods for harmonic analysis of soil are provided herein. Some methods include converting a first frequency of an operating signal into a second, higher frequency relative to the first frequency to create a stimulating signal, transmitting the stimulating signal into soil, and determining attenuation based on a comparison of a responsive signal and the operating signal.

Abstract: An angled face cap probe includes a housing having a radially inner end and a radially outer end, defining a cavity, and configured to be located radially outward from an airfoil. The angled face cap probe further includes a sensor located in the cavity at the radially inner end of the housing, having a sensor body with a sensing face that is angled to match or substantially match an angle of a radially outward face the airfoil, and having a sensor flat that is elongated in a first direction. The angled face cap probe further includes an outer cap located in the cavity, coupled to the housing, and having an outer cap main body and cap legs that extend radially inward from the outer cap main body to interface with the sensor flat to resist rotation of the sensor relative to the housing.

Abstract: A touch input sensing device configured to be added to an electronic device, the electronic device including a touch input unit, the touch input unit including a first touch member integrated with a housing. The touch input sensing device includes a resonant circuit configured to generate a resonance signal having a resonant frequency that varies based on a touch of the touch input unit, a digital frequency counter configured to count a reference frequency signal based on the resonance signal, or count the resonance signal based on the reference frequency signal, to generate a count value, and a touch detector configured to detect whether the touch of the touch input unit has occurred based on the count value generated by the digital frequency counter, and output a touch detection signal indicating whether the touch has occurred.

Abstract: A process includes receiving an associated input signal via a receiver electrode of a sensor array, the associated input signal indicative of an associated mutual capacitance of the receiver electrode; adding a balancing signal to the associated input signal to generate a balanced input signal at least partially responsive to a number of sensor nodes at the receiver electrode; generating a voltage signal indicative of the associated mutual capacitance of the receiver electrode at least partially responsive to a balanced input signal; and generating a digital value representative of the voltage signal.

Abstract: Embodiments are disclosed for a low-frequency detection and ranging. In an embodiment, an apparatus comprises: an open electrode; an alternating current (AC) voltage source configured to supply an excitation voltage to the open electrode at an excitation frequency; a resonant circuit coupled to the open electrode, the resonant circuit configured to oscillate when an object is within a detection distance of the open electrode; one or more processors configured to: obtain time domain samples of an output voltage of the resonant circuit when the resonant circuit is oscillating; convert the time domain samples into frequency domain samples; for each frequency domain sample, determine an amplitude difference and a phase difference as compared to an amplitude and phase of the excitation voltage; and determine a material class of the object based on the amplitude difference and the phase difference.

Abstract: A method for monitoring a biotechnological process, wherein starting materials are converted into products via a biomass and important process parameters for monitoring are identified during the process, where during the process, a current concentration of the biomass utilized in the process is recurrently estimated, current measurement values of measurable process parameters are then recurrently determined on a recurring basis and current values for additional process parameters are identified therefrom, where the current measurement values of the measurable process parameters and the current determined values of the additional process parameters are based on the respective temporally correlating concentration of biomass and where, from a combination of the current concentration of biomass and the current measurement values of the measurable process parameters and the identified current values of the additional process parameters, current, cell-specific metabolic indicators are then derived which are then us

Abstract: A valve device that includes a valve body; a valve shaft configured to rotate the valve body; a coil spring being electrically conductive and configured to be twisted with rotation of the valve body and the valve shaft; a first conductive member being electrically conductive and facing an inner circumferential surface or an outer circumferential surface of the coil spring in a radial direction of the coil spring; and a first detector configured to detect at least one of a rotation angle of the valve body or a rotation angle of the valve shaft based on an electrostatic capacitance between the coil spring and the first conductive member, the electrostatic capacitance changing according to a state of the coil spring that changes with the rotation of the valve body and the valve shaft.

Abstract: Systems, methods, and devices improve the sensitivity of capacitive sensors. Devices may include an attenuator configured to receive an input from at least one sense electrode of a capacitive sensing device. The attenuator may be included in a sensing channel of a capacitive sensor. Devices may further include a signal generator coupled to an input of the attenuator. The signal generator may include one or more processors configured to generate a sinusoidal signal based, at least in part, on one or more noise characteristics of a scan sequence associated with one or more transmit electrodes of the capacitive sensing device, and provide the sinusoidal signal to the input of the attenuator.

Abstract: A capacitance detection circuit for measuring an electrostatic capacitance, includes: a control signal generator configured to generate a control signal; a drive circuit having a push-pull type output stage and configured to apply a drive voltage to the electrostatic capacitance according to the control signal; a current detection circuit configured to generate a detection current which is a replica of a current flowing through the output stage of the drive circuit; and an integrating circuit configured to integrate the detection current to generate a detection voltage.

Abstract: A processing system is disclosed. The processing system includes an amplifier configured to generate a feedback signal by amplifying each of multiple reduced noise signals based on a gain value and a cardinality of the reduced noise signals. The processing system also includes multiple charge integrators configured to obtain resulting signals from capacitive sensor electrodes coupled to a noise source and generate the reduced noise signals by mitigating noise in the resulting signals using the feedback signal.

Abstract: A load monitoring system for a facility includes a computer system configured to execute a model of the object, the model configured to estimate a state of the object as a function of measured values of at least one characteristic of the object, receive at least one measured value of the at least one characteristic of the object, and execute, by the computer system, the model to compute an estimated state of the object.

Abstract: Aspects of the disclosure are directed to self-capacitance measurement and cancellation. In accordance with one aspect, a self-capacitance cancellation circuit includes an input amplifier, wherein the input amplifier comprises a non-inverting input, an inverting input and an output; a coherent current source coupled to the inverting input; a feedback network coupled to the output; and a capacitance coupled to the inverting input.

Abstract: A water content measuring device measures water content of an object to be measured. The water content measuring device includes two plate members that are disposed facing each other, a current generating unit, a measuring unit, and an arithmetic processing unit. The current generating unit generates current supplied between the two plate members. The measuring unit measures electrostatic capacitance generated by the current supplied between the two plate members. The arithmetic processing unit is configured to convert the electrostatic capacitance measured by the measuring unit to water content. Two plate members each have a shape or are disposed such that at least two points on a leading edge of the object enter between the two plate members at different timings in a direction perpendicular to a passing direction in which the object passes through the two plate members.

Abstract: A signal processing circuit of a touch device including an operational amplifier, a feedback resistor and a step current circuit is provided. The feedback resistor connects between a negative input and an output terminal of the operational amplifier. The step current circuit is coupled to the negative input of the operational amplifier and configured to provide or draw a step current to reduce the current flowing through the feedback resistor so as to compensate the voltage offset of the operational amplifier.

Abstract: A capacitive measurement device for indicating when two surfaces moving relative to each other are spaced less than a predetermined distance apart. The device comprises a probe having an elongated conductor, an insulating core, a conducting inner guard, an insulating interlayer, and a conducting sheath. A portion of the conductor, insulating core and conducting inner guard form a probe tip which extends beyond the insulating interlayer and conducting sheath by a predetermined offset. The probe is configured to extend from a first surface by a predetermined distance and to generate a signal when the tip is contacted by a second surface.

Abstract: In accordance with one or more aspects of the present disclosure, a method including supplying a first voltage input to a Coriolis vibratory gyroscope at a first bias voltage; supplying a second voltage input to the Coriolis vibratory gyroscope at a second bias voltage, the second bias voltage being different than the first bias voltage; detecting a difference in responses of the Coriolis vibratory gyroscope due to the first bias voltage and the second bias voltage; and determining a gyro rate of the Coriolis vibratory gyroscope as a function of the difference in responses and a correction term.

Abstract: An engine probe system for monitoring a moving engine element. The probe system includes a capacitive sensor (1) including a sensing electrode (5) defining one of the electrodes of a capacitor and an output lead for coupling the sensing electrode (5) to data processing means for monitoring changes in the capacitance of the capacitor including the sensing electrode. The output lead includes a first conductor for connecting the sensing electrode to the data processing means, an insulation jacket surrounding the first conductor, and a flexible conduit (11) surrounding the insulation jacket and defining a fluid passage between the insulation jacket and the flexible conduit.

Abstract: A probe assembly includes plural capacitive contacts that are separate from each other and a conductive depletion gate disposed between and separating the contacts from each other. The depletion gate is configured to receive a direct electric voltage to deplete regions of a sample under test of electrons. The contacts are configured to be placed in close proximity to a buried conducting layer in the sample under test without engaging the buried conducting layer, thereby capacitively coupling to the buried conducting layer. A first subset of the capacitive contacts is configured to apply an alternating electric current to a portion of the sample under test and a second subset of the capacitive contacts is configured to sense an alternating voltage response of the portion of the sample under test to characterize one or more electrical properties of the sample under test without the capacitive contact with the buried conductive layer.

Abstract: Foreign metal inspection equipment is provided with: a conveying device for conveying a sample to be subjected to inspection; electrodes positioned so as to face the surface of the sample; a measurement device for measuring the capacitance between the electrodes and the sample being conveyed by the conveying device; and a processing unit that inspects for foreign metal mixed in the sample on the basis of the change in capacitance measured by the measurement device.

Abstract: A method and a system for three-phase detection of a three-phase electric device are provided. The system includes a testing circuit and a comparison module. The testing circuit generates two reference voltages by using the three phase voltages of the three-phase electric device. The two reference voltages are the first and second phase voltages with reference to the third phase voltage, respectively. Three-phase detection is performed by comparing the two reference voltages for a determined number of times. After testing is completed, the testing circuit is switched off by the comparison module, to save power.

Abstract: An apparatus for digitizing an impedance is provided that comprises a first impedance element having a first impedance that varies with a property to be measured and a second impedance element having a second impedance. The apparatus also includes a drive signal generator for applying a first alternating drive signal to the first impedance element and a second alternating drive signal to the second impedance element. An analog-to-digital converter, ADC, receives a resultant signal comprising the combination of the signals produced by the application of the first and second alternating drive signals to the first and second impedance elements. The first alternating drive signal is phase shifted relative to the second alternating drive signal such that the resultant signal received and sampled by the ADC sequentially relates to the sum of, and the difference between, the first and second impedances.

Abstract: The present invention relates to a dynamic height adjusting system and method that uses capacitance for a head assembly of a laser processing system throughout a process cycle. The proposed system and method involves use of a single frequency in which a change in phase is measured and processed to determine changes in height and distance between a work piece with an increased reliability. The system further enables operative computerized processor control and substantial improvements in process control signal and feedback distribution throughout an integrated system and optional remote interfaces.

Abstract: Apparatuses and methods of input attenuator circuits are described. One sensing circuit includes an attenuator circuit to receive a signal from an electrode of a sense array. The attenuator circuit is configured to attenuate input current of the signal. The attenuator circuit includes an attenuation matrix including an input terminal to receive the signal and multiple resistors. The attenuation matrix is configured to split the input current into an output current of the attenuation signal on a first output terminal and a second output current on a second output terminal. The attenuation matrix is to output the attenuated signal on the first output terminal to an integrator of the sensing circuit. The attenuator circuit also includes a buffer coupled between the attenuation matrix and the integrator. The buffer is configured to maintain a substantially same voltage at the first output terminal and the second output terminal.

Abstract: A visually and remotely readable apparatus is provided which comprises a plurality of sensing units, a control unit and a flexible printed cable (FPC) to connect two units for exchanging information therebetween. A preferable structure of the sensing unit includes a fixed part secured to the body of the apparatus and two oppositely positioned rotatable parts, where two rotatable parts mounted on a common shaft with the fixed part arranged therebetween forming two angular position sensors. Each sensor is based on the capacitive coupling between two working surfaces of the rotatable part and the respective working surfaces of the fixed part with the electrodes are secured thereto. Two working surfaces of one part are confronted with two respective working surfaces of another part forming two working surface pair. Each sensor has two working surface pairs, one working surface pair is sensing pair for sensing angular position; another is coupling pair for coupling sensing signals.

Abstract: A MEMS capacitive sensing interface includes a sense capacitor having a first terminal and a second terminal, and having associated therewith a first electrostatic force. Further included in the MEMS capacitive sensing interface is a feedback capacitor having a third terminal and a fourth terminal, the feedback capacitor having associated therewith a second electrostatic force. The second and the fourth terminals are coupled to a common mass, and a net electrostatic force includes the first and second electrostatic forces acting on the common mass. Further, a capacitance measurement circuit measures the sense capacitance and couples the first terminal and the third terminal. The capacitance measurement circuit, the sense capacitor, and the feedback capacitor define a feedback loop that substantially eliminates dependence of the net electrostatic force on a position of the common mass.

Abstract: Systems and methods are provided to determine a capacitance of an electrochemical biosensor test cell of a test strip via determination of a phase angle between an output signal and input oscillating signal from the electrochemical test cell with measurement of an amplitude of the output signal from the electrochemical test cell along with conversion of the measured amplitude into a complex impedance of the electrochemical test cell based on the oscillating signal, phase angle and electrical resistance between the test cell and the connectors to derive a capacitance of the electrochemical test cell based on the complex impedance and predetermined frequency of the electrochemical test cell.

Abstract: The invention relates to a capacitive position encoder (1), comprising at least one capacitor with a first capacitor plate and a second capacitor plate, a dielectric modulator that is movably arranged between said first capacitor plate and said second capacitor plate, a signal source (11) for providing a phase-shifted excitation signal to the first capacitor plate of said at least one capacitor, and a charge amplifier (20) that is electrically connected to the second capacitor plate of said at least one capacitor, wherein a feedback loop (21) of the charge amplifier (20) comprises a feedback capacitor (Cf), wherein the capacitive position encoder (1) also comprises a shock cancellation circuit (30) that forms a parallel circuit with the feedback loop (21) including the feedback capacitor (Cf) and that the shock cancellation circuit (30) comprises a low pass filter (31).

Abstract: A system and method for providing electromagnetic imaging through electroquasistatic sensing contains an electromagnetic sensor for imaging a sample. The electromagnetic sensor contains drive/sense electronics and a pixelated sensor array having an array of capacitive sensor electrodes that source electric fields that interact with the sample, and wherein the electrodes are individually drivable by the drive/sense electronics in a coordinated manner to establish a desired temporal and spatial pattern in which electrical properties of the electrodes are used to generate an image. Other components of the system include a precision motion controller, sensor head and associated electronics, and a computer for performing data acquisition and signal inversion.

Abstract: Apparatuses and methods of input attenuator circuits are described. One sensing circuit includes an attenuator circuit to receive a signal from an electrode of a sense array. The attenuator circuit is configured to attenuate input current of the signal. The attenuator circuit includes an attenuation matrix including an input terminal to receive the signal and multiple resistors. The attenuation matrix is configured to split the input current into an output current of the attenuation signal on a first output terminal and a second output current on a second output terminal. The attenuation matrix is to output the attenuated signal on the first output terminal to an integrator of the sensing circuit. The attenuator circuit also includes a buffer coupled between the attenuation matrix and the integrator. The buffer is configured to maintain a substantially same voltage at the first output terminal and the second output terminal.

Abstract: A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

Abstract: Sinusoidal drive is used, and a coefficient table for a plurality of predetermined phases is established, wherein each predetermined phase is designated with a coefficient. A sinusoidal wave is measured at the plurality of predetermined phases of each half cycle to produce measured signals, and each of the measured signals is multiplied with the coefficient corresponding to the phase at which the signal is measured to produce a weighted measured signal. Then, the weighted measured signals are summed to produce a complete measured signal.

Abstract: A capacitance measuring system, including: a calibration capacitor; first circuitry for sensing an input current at an input thereof and generating an output signal that is based upon a capacitance appearing at the input of the first circuitry; and multiplexer circuitry, coupled between the input of the first circuitry and a terminal of each of the capacitor to be measured and the calibration capacitor, for selectively coupling the terminal of each, one at a time, to the input of the first circuitry while the terminal not coupled to the input of the conversion circuitry is coupled to a ground reference; and controller circuitry for calculating a capacitance of the capacitor to be measured based upon the output signal of the first circuitry when the capacitor to be measured is coupled to the input thereof and upon the output signal of the first circuitry when the calibration capacitor is coupled to the input thereof.

Abstract: Changes of the stray capacitances of a large number of sensing electrodes can be detected simultaneously. Further, even if a stray capacitance changes slightly, an input operation to a sensing electrode can be detected based on elapsed time until the electric potential of the sensing electrode becomes the same as a threshold potential. The stray capacitance of a sensing electrode and a resistor of the sensing electrode form a CR time constant circuit. Charge or discharge of the stray capacitance of the sensing electrode is controlled while a rest time in a predetermined time ratio is set. A stray capacitance that slightly increases in response to an input operation made near a sensing electrode can be detected by detecting the stray capacitance in extended elapsed time until the electric potential of the sensing electrode becomes the same as the threshold potential.

Abstract: The invention relates to a sensor for detecting an object. The sensor includes a probe electrode for forming a measuring capacitance with the object to be detected, a charging generator for generating an alternating charging voltage, wherein the probe electrode is charged by means of the alternating charging voltage, an amplifier for amplifying a voltage across the measuring capacitance, wherein the amplifier includes a first supply connection and a second supply connection, electronic means for processing signals outputted at an output of the amplifier to form at least one output signal and at least one sensor output for outputting the at least one output signal.

Abstract: According to the present invention, a small impedance detection circuit capable of accurately detecting the impedance of an object to be measured and an adjustment method of an impedance detection circuit can be provided. In the impedance detection circuit according to the present invention, an AC signal generator outputs an AC signal. A detection circuit, which is connected to a circuit to be measured, applies an AC signal to the circuit to be measured. Further, the detection circuit outputs a first signal corresponding to the composite impedance of the impedance of the circuit to be measured and a parasitic impedance. A correction circuit outputs a second signal in synchronization with the first signal. A subtraction circuit outputs a detection signal obtained by subtracting the second signal from the first signal.

Abstract: A method for operating a capacitive position sensor includes providing excitation signals driving each conductive element. The excitation signals are periodic in 2?, with each set of conductive elements being provided with n different excitation signals. The different excitation signals differ in phase, wherein in a functionality check mode, the excitation signal that in a measurement mode is applied to one of the conductive elements in the functionality check mode is applied to a different one of the conductive elements. The different conductive element is the k-th conductive element counted from the one of the conductive elements, with k being an integer of 1 to n?1 and this shift of excitation signals is applied to all conductive elements. The capacitive position sensor includes a stator having a transmitter with N sets of conductive elements, each set having n conductive elements formed in a linear or circular arrangement thereon.

Abstract: A capacitive sensing circuit is disclosed, wherein the transimpedance amplifier in front of the mixer in prior art is removed respectively replaced by an amplifier with low gain and consequently high dynamic range. The mixer DC offset voltage or current together with the large amplification factor required after the mixer now would result in an inacceptable DC offset at the output of the signal chain. In order to eliminate the effect of the mixer offset, the amplifying stages after the mixer are AC coupled to the mixer output and one of the signals entering the mixer is phase modulated or amplitude modulated with a known low frequency signal. An additional mixer after the AC coupled amplifying stages is driven with the same low frequency modulating signal, resulting in the wanted DC output signal responsive to the capacitance to be measured.

Abstract: An object of the invention is to prevent a human error, greatly reducing man-hours and to securely identify a core. To achieve the object, a request for a serial number is first made via a conductor of a core from a recognition unit that functions as a master to a recognition unit that functions as a slave. Next, the recognition unit as the slave reads a serial number for an IC tag and transmits the serial number via the conductor of the core. The recognition unit as the master receives the serial number transmitted from the recognition unit as the slave and collates the serial number and a serial number stored in an IC tag. It is ascertained by the collation that the conduction of the core is correctly made and it is displayed on a display of the recognition unit as the master and others that no disconnection on the way and no error in selecting an end of wiring are caused.

Abstract: A device for an electric hand-held device for detecting the hand-held device being clasped by a hand, has at least one transmitting electrode, which can emit an alternating electric field, and at least one receiving electrode, in which the alternating electric field can be coupled at least partially, wherein the at least one transmitting electrode and the at least one receiving electrode can be arranged on the hand-held device such that each of them is at least partially covered by the hand when the hand-held device is being clasped by the hand. When the hand-held device is being clasped by the hand, a first portion of the alternating electric field emitted by the transmitting electrode can be coupled via the hand into the receiving electrode, wherein at least the first portion of the alternating electric field is a characteristic representative of the hand-held device being clasped by the hand.

Abstract: Current Voltage and Capacitance Voltage (IV and CV) measurements are critical in measurement of properties of electronic materials especially semiconductors. A semiconductor testing device to accomplish IV and CV measurement supports a semiconductor wafer and provides a probe for contacting a surface on the wafer under control of an atomic Force Microscope or similar probing device for positioning the probe to a desired measurement point on the wafer surface. Detection of contact by the probe on the surface is accomplished and test voltage is supplied to the semiconductor wafer. A first circuit for measuring capacitance sensed by the probe based on the test voltage and a complimentary circuit for measuring Fowler Nordheim current sensed by the probe based on the test voltage are employed with the probe allowing the calculation of characteristics of the semiconductor wafer based on the measured capacitance and Fowler Nordheim current.

Abstract: A MEMS component is monitored to determine its status. Sensors are deployed to sense the MEMS component and produce detection signals that are analyzed to determine the MEMS component state. An indicator device alerts a user of the status, particularly if the MEMS component has failed. Additionally, the MEMS component monitoring system may be practiced as a design structure encoded on computer readable storage media as part of a circuit design system.

Abstract: A method of detecting rubs during operation of a turbomachine comprising at least one rotating object having a tip and a shelf is provided. The method includes generating signals representative of a sensed parameter and processing the signals to generate height versus time data for the tip. The height of the tip corresponds to the distance between the tip and the shelf. The method further includes monitoring the height versus time data, in order to determine whether a change in the height data exceeds a threshold value, and detecting a rub of the rotating object(s) on a second object, when the change in the height data exceeds the threshold value. A rub detection system for a turbomachine and a turbine engine system with rub detection are also provided.

Abstract: A device and method of determining a capacitance of a device is provided, which in one embodiment includes connecting a first terminal of a capacitor having a known capacitance to the first terminal of the device, applying an AC voltage to the first terminal of the device and the first terminal of the capacitor, measuring a current through the capacitor, measuring a current through the device, determining a first voltage across the device as a function of time, computing a capacitance of the device as a function of time by multiplying the capacitance of the capacitor by the ratio of the current through the device to the current through the capacitor, determining a capacitance of the device as a function of voltage based on the capacitance as a function of time and the first voltage across the device as a function of time, and outputting data of the first capacitance of the device as a function of voltage.

Abstract: An improved biometric data sensing circuit, for example adapted for fingerprint sensing, uses a charge subtraction technique at the input of the circuit integrator to cancel the so called “common mode” signal from the circuit output. The result is an output signal that is (a) linear, (b) free from any amplification effect due to the presence of the detected object (e.g. a finger), and (c) indicative of the detected object's fine surface geometry (i.e., indicative of the fingerprint's ridges and valleys).

Abstract: An apparatus for digitising an impedance is provided that comprises a first impedance element having a first impedance that varies with a property to be measured and a second impedance element having a second impedance. The apparatus also includes a drive signal generator for applying a first alternating drive signal to the first impedance element and a second alternating drive signal to the second impedance element. An analogue-to-digital converter, ADC, receives a resultant signal comprising the combination of the signals produced by the application of the first and second alternating drive signals to the first and second impedance elements. The first alternating drive signal is phase shifted relative to the second alternating drive signal such that the resultant signal received and sampled by the ADC sequentially relates to the sum of, and the difference between, the first and second impedances.

Abstract: Methods and systems are provided to determine capacitance of the electrochemical test cell.

Abstract: Apparatus and methods are disclosed for obtaining an image of the impedance properties of an object by inferring a measure of straight-line path impedance along a plurality of paths from a plurality of current amplitude and phase measurements made between combinations of electrodes placed at selected points, and/or from measurements of the intensity of the electromagnetic signal emitted when an alternating current is made to resonate along the straight line path.

Abstract: A position encoder is described that generates a signal whose phase varies with a position to be determined. A phase detector determines a first phase measurement of the sensor signal during a first mode and a second phase measurement of said sensor signal during a second mode. The phase detector then differences the first and second phase measurements to obtain a phase difference measurement, which it uses to determine an indication of the position to be sensed. A controller controls a signal generator in order to set a start phase of signals generated in at least one of the first and second modes so that the timings at which said sensor signal crosses a reference level are substantially the same.